74,258 research outputs found
Controlled cavity-QED using a photonic crystal waveguide-cavity system
We introduce a photonic crystal waveguide-cavity system for controlling
single photon cavity-QED processes. Exploiting Bloch mode analysis, and
medium-dependent Green function techniques, we demonstrate that the propagation
of single photons can be accurately described analytically, for integrated
periodic waveguides with little more than four unit cells, including an output
coupler. We verify our analytical approach by comparing to rigorous numerical
calculations for a range of photonic crystal waveguide lengths. This allows one
to nano-engineer various regimes of cavity-QED with unprecedented control. We
demonstrate Purcell factors of greater than 1000 and on-chip single photon beta
factors of about 80% efficiency. Both weak and strong coupling regimes are
investigated, and the important role of waveguide length on the output emission
spectra is shown, for vertically emitted emission and output waveguide
emission
Exploiting long-range disorder in slow-light photonic crystal waveguides
The interplay between order and disorder in photonic lattices opens up a wide
range of novel optical scattering mechanisms, resonances, and applications that
can be obscured by typical ordered design approaches to photonics. Striking
examples include Anderson localization, random lasers, and visible light
scattering in biophotonic structures such as butterfly wings. In this work, we
present a profound example of light localization in photonic crystal waveguides
by introducing long-range correlated disorder. Using a rigorous
three-dimensional Bloch mode expansion technique, we demonstrate how inter-hole
correlations have a negative contribution to the total out-of-plane radiative
losses, leading to a pronounced enhancement of the quality factor, , and
cavity figures of merit in the long-range correlation regime.
Subsequently, the intensity fluctuations of the system are shown to globally
increase with the correlation length, highlighting the non-trivial role of
long-range disorder on the underlying scattering mechanisms. We also explore
the possibility of creating ultra-high quality cavity modes via inter-hole
correlations, which have various functionalities in chip-based nonlinear optics
and waveguide cavity-quantum electrodynamics.Comment: Updated version with DO
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